An example of a front fork that supports a front wheel of a straddle-riding vehicle includes one that is interposed between a vehicle body and a front wheel axle in a straddle-riding vehicle, exerting a damping force. Such a front fork typically includes a fork main body that is configured to extend/contract, provided with a vehicle body tube connected to the vehicle body of the straddle-riding vehicle and an axle tube fitted with the vehicle body tube and connected to the front wheel axle; and a damper cartridge that is housed in the fork main body and is configured to exert a damping force in accordance with extension/contraction of the fork main body.
The front fork described above may be provided with an adjuster for adjusting damping force characteristics so that the damping force characteristics can be changed to a characteristic desired by a user. For example, a front fork disclosed in JP-5116874-B2 adjusts spring forces of a spring that presses a valve for opening/closing a passage that connects two working chambers provided in a damper cartridge, and adjusts degrees of opening of a needle valve that bypasses this passage and narrows down a bypass passage communicating the two working chambers.
This front fork includes a valve adjustment rod configured to adjust the degrees of opening of the needle valve; and a spring adjustment rod provided to an outer periphery of this adjustment rod, configured to adjust the spring forces of the spring, and having a tubular shape. Two adjustment portions corresponding to the valve adjustment rod and the spring adjustment rod are provided to a cap provided to an upper end opening of a vehicle body tube. A valve adjuster nut that moves axially with respect to the vehicle body tube by rotation of the adjustment portion in the valve side is brought into contact with the valve adjustment rod, and a spring adjuster nut that moves axially with respect to the vehicle body tube by rotation of the adjustment portion in the spring side is brought into contact with the spring adjustment rod.
When the adjustment portion in the valve side is rotated, the valve adjuster nut moves upward and downward with respect to the vehicle body tube, and the valve adjustment rod can be moved upward and downward so that the degrees of opening of the needle valve can be adjusted. Furthermore, when the adjustment portion in the spring side is rotated, the spring adjuster nut moves upward and downward with respect to the vehicle body tube, and the spring adjustment rod can be moved upward and downward so that the spring forces of the spring can be adjusted. Accordingly, in this front fork, a user can easily change damping force characteristics of the front fork.